August is National Golf Month. You may have a lot of golf clubs in your attic, but they won't be worth this much! Arnold Palmer's first golf clubs sold for $43,020 at a Heritage auction in Baltimore. Provenance (history) matters.

The 1940s set has seven First Flight hickory-shaft irons and two Louisville woods—nine clubs total—and the tweed and leather Spalding golf bag that Palmer once carried around Pennsylvania golf courses. There was ample documentation—a letter from Palmer certifying that the clubs were his, three photos of the clubs signed by Palmer, a photocopy of the 1945 Latrobe High School yearbook's golf team page picturing Palmer, and other pictures and copies of articles, testifying to the golf clubs' provenance—who owned them, when and where.

Find prices of less historic golf clubs and other sports collectibles in the FREE online price guide at Kovels.com. Still more prices are in the just-published Kovels' Antiques & Collectibles Price Guide 2013, available at bookstores and online now.